This approach is usually less stable and cannot generate the low frequencies that a heterodyne oscillator can.
2.
Better designs ( e . g ., Moog, Theremax ) may use two pairs of heterodyne oscillators, for both pitch and volume.
3.
The heterodyne oscillator is the ancestor of the " beat frequency oscillator " ( BFO ) which is used to receive radiotelegraphy in communications receivers today.
4.
Modern circuit designs often simplify this circuit and avoid the complexity of two heterodyne oscillators by having a single pitch oscillator, akin to the original theremin's volume circuit.
5.
The advantage of using a VFO as a heterodyning oscillator is that only a small portion of the radio receiver ( the sections before the mixer such as the preamplifier ) need to have a wide bandwidth.
6.
The heterodyne oscillator had to be retuned each time the receiver was tuned to a new station, but in modern superheterodyne receivers the BFO signal beats with the fixed intermediate frequency, so the beat frequency oscillator can be a fixed frequency.
7.
It covered a greater portion of the high frequency ( HF ) and medium wave spectrum than did the SW-4, by using a large set of selectable heterodyne oscillator crystals for selecting the tuning range, each covering a 500 kHz wide segment.
8.
The-3A and-3C units were identical to the-3 and-3B units, respectively, except they provided an extra set of heterodyne oscillator crystals enabling them to cover extra bands useful for military, amateur and MARS operation, where operation just outside the regular amateur bands was necessary.
परिभाषा
an oscillator whose output heterodynes with the incoming radio signal to produce sum and difference tones पर्याय: local oscillator,
मोबाइल